From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=74.125.82.172 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794672563; b=dpsSX8FMVRQfzxbM4d6oYeOOAx2J/WqrEETOpTWXruhYykU0bOzRardeFG/DT6dv4nF6 pQmDIc7lpdtITzCIwt23tWuVyLp/JaQhWpcGGR5vO9uskY5GYqQAXUh002/CYulEj3pXy sSibLy0xBCD6ThjRMfmyDkoRiInXjHyCbnApnzlltMWD97qjhsQdoM/5/Gwu/KIeF+DAn VKu8S/DZoKPhmRXv+JAnfjlnykf3Qc9FOxJyNItnWsB579mtpEge7P68m2S77SvA3pW4w 05uDJauiu9a7clGTD/Bgkl4wJN13AQhW/cMyl3nKkaOwiMhwIl+2toozhif0qaSvUfg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794672563; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: From:To:Cc:Subject:Date:Message-ID:X-Mailer:In-Reply-To:References: MIME-Version:Content-Transfer-Encoding; bh=EfZAm8HK5M4blUNFdDl+epKKwi55wmzsTvrZgcxUZEg=; b=cFDqjSwLToGALkdvpKCfyDRcNnVXvafzTmOp6uAEfqhLSdbCrKzwUfY5SJZ7DnMCO2sX eVGfigbHUVRLMBBJaIjvEDnDyX7v8fDo8EUfsZzVGWeoLCkCH/X9eyCAkl2S5qzcaAtCa 1ONI7HU/4UvW0uexKmyeWt8pAzEPh+fKh3fSjsRTnglg7nRDt3RZaEU0XDurUY3kkU6ec EuHMQMciMuOH1KoUwo5lXsqSPzplCpR3V9XnZS7qd9792UKtSt7RQa5Y6fJRkx/W8+vca n82ITr0jCjtqEK1IGJcJGBUWeFtvbKJgAvrI05F9YcDteHr7IOutWETu/C4KPghpq2w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=fyiEkrQ7; arc=none smtp.remote-ip=74.125.82.172 Received: from mail-dy1-f172.google.com (mail-dy1-f172.google.com [74.125.82.172]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7C2B3606A336 for ; Sat, 14 Nov 2026 16:09:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 7C2B3606A336 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=fyiEkrQ7 Received: by mail-dy1-f172.google.com with SMTP id 5a478bee46e88-3791619605cso4134109eec.0 for ; Sat, 14 Nov 2026 08:09:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1794672563; x=1795277363; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=EfZAm8HK5M4blUNFdDl+epKKwi55wmzsTvrZgcxUZEg=; b=fyiEkrQ7Mr3ulVKXsUkU7aXda0e8efD4fC35q2/ZvGd0LwHuIdbauFljjdLSpCj4Ad IOgeuwjaHlMYbzDDUFJyrfz/7/dSuKNwWd0U+YxbvXTjUdg4OCb4ys9BEUlzHZuBg/iP MQLKaZswKcuJ0Z13SOsSaRgTiHqO470hlZ9K7hO6x6yNgk6iVRXGWtz0v5zaiAAXe0dX E4IpUtxm9SS6fRMBctHOKFSj5WTtYDm1nSMQ2sJoDWq0lvnPPi15o+uTHcV52cZBch96 s7xXAuJFtYfF+qyVMnoQfl/8PrEtX/EZSqwN0jHDelmBV//UcGkyLmPmU244LPhFmzim FHIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1794672563; x=1795277363; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=EfZAm8HK5M4blUNFdDl+epKKwi55wmzsTvrZgcxUZEg=; b=A23d+3KlM7BkfAKqq4KjHeuzdAnYR6HBCwl/0L2+UgXnoZJepY19LjHR82HJdL+8Q8 rcPcF6xJrb3hgaSFG6bzTAeW/N/u937HbYMe4nbak4HbcixkT48nVx6NwlgU7bmxASBK Y30SAtKMJdDZQFoEvWLYNglyEAxf8P6k8L/19bdPtznwWRGwsN28r2Zg8ARrJza/J6xD 9XSYvuS3Z3Lxoo3RaSoCdjKibMjwBox7Gf9JuS07Pi+YMpVJ6VYdM2hAviJR+LNNGto/ eJmZLoFSkvbzadmxLErsf4Q4gc7OgaNGVwdutARuFzt8QB3YsLG/roCO0nPfyiD/IveR 8CdA== X-Forwarded-Encrypted: i=1; AL+hErEEzN9xaW7RR2DiNSTrBTiezMVsM/5QH+Zls4DEvuh5MjeUWHDgflmu70yRO4ElcsHE+5P/MVT4H2pkBNU=@vger.kernel.org X-Gm-Message-State: APuU4Z/esKGAsYCC5R5NspTcE6WmPmiSPLDmv8nx8grmDYTolWkeTPfq Tuxki0gr3agE7eFOuOLGH1pbRlwd62EMDZTkVgPB2pZGOE9wCcq/pVA= X-Gm-Gg: AYBFou23ll8CmSmrnd0lokcnsp4sGZDgsM28yZfDk6N0pVTwBv3FmoV5RNdHrOACSPC XdB+yQaRYKBUUdRVRmHnX1Gd4zuPrA4sBRtQgHONEr2nc7T/YaaR0DggoSBW0qNcmhegsxeoYxn xqPvlRqTPQ1fiMKOqQxSs10ATMXdPPyYazGBrNB3/IvhJxy3sRiVkicAX8v1NNLussoDAh7NxX8 bllyb1yFFVntXkiP7e8Zp9Bv7DCnms8xfXE972Qydoj/NYg6REFdEiF/oOWT1F6n81lZUqf3gO1 lo03oT5wo6Ux/0q9AiJgmuUHZo+6FjchFuReydDV7/7nYtP/xwgGobN8fFeszEWrJ41zU8sVcX7 oXSV+TX3xQYnfWVVZ52glWUFwwB6Xd6tNaPNqN27NVgG02S4lcbPwBDTEukY4rmC+0EBfRr86Am wm+SKY+qAGXe9hn31FyevJ17Aksd7OjFlHhsyotuyc9IzTvBqu+wCnrnoxk/TMCwHzYDNw/5pB5 YYh8Dt4BGeNrmoHEDZQ4iUy71wxz11cd9EL5iYlGE/6RSPI7suNNlNtK9WkQs3NotZj3rspoYHJ 75w0rl44JZxwVZA/AYQJam/Eae/yNhR7ZPaaL73PG5xkkz9iM4bIgO0nKmVZ5sV84w== X-Received: by 2002:a05:693c:4152:10b0:36a:4a68:84e5 with SMTP id 5a478bee46e88-379659c6839mr6027249eec.8.1794672562295; Sat, 14 Nov 2026 08:09:22 -0800 (PST) Received: from at-Standard-PC-Q35-ICH9-2009 ([106.202.127.108]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-37956bb0919sm17567582eec.29.2026.11.14.08.09.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 14 Nov 2026 08:09:21 -0800 (PST) From: Atharva Tiwari To: Cc: Andre Eikmeyer , Sebastian Zygadlo , Yossef Osman , Atharva Tiwari , Bjorn Helgaas , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), "H. Peter Anvin" , Alex Deucher , =?UTF-8?q?Christian=20K=C3=B6nig?= , David Airlie , Simona Vetter , Harry Wentland , Leo Li , Rodrigo Siqueira , Kenneth Feng , Hans de Goede , =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= , linux-pci@vger.kernel.org (open list:PCI SUBSYSTEM), linux-kernel@vger.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)), amd-gfx@lists.freedesktop.org (open list:RADEON and AMDGPU DRM DRIVERS), dri-devel@lists.freedesktop.org (open list:DRM DRIVERS), platform-driver-x86@vger.kernel.org (open list:X86 PLATFORM DRIVERS) Subject: [PATCH v2 05/12] platform/apple-gmux: Write switch state to EFI on MMIO devices Date: Sat, 14 Nov 2026 11:06:29 -0500 Message-ID: <20261114160731.3756-6-atharvatiwarilinuxdev@gmail.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261114160731.3756-1-atharvatiwarilinuxdev@gmail.com> References: <20261114160731.3756-1-atharvatiwarilinuxdev@gmail.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Andre Eikmeyer On T2 devices (MMIO), the T2 coprocessor reads gpu-active efi variable, and macOS seems to write it, so to properly communciate to the T2 coprocessor, we write gpu-active. Tested-by: Sebastian Zygadlo Tested-by: Yossef Osman Co-developed: Atharva Tiwari Signed-off-by: Atharva Tiwari Signed-off-by: Andre Eikmeyer --- drivers/platform/x86/Kconfig | 1 + drivers/platform/x86/apple-gmux.c | 40 +++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index c37e76066..01895d511 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -217,6 +217,7 @@ config APPLE_GMUX depends on ACPI && PCI depends on PNP depends on BACKLIGHT_CLASS_DEVICE + depends on EFI help This driver provides support for the gmux device found on many Apple laptops, which controls the display mux for the hybrid diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c index 37ba20779..c4a953b5b 100644 --- a/drivers/platform/x86/apple-gmux.c +++ b/drivers/platform/x86/apple-gmux.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include @@ -489,6 +490,32 @@ static void gmux_write_switch_state(struct apple_gmux_data *gmux_data) gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3); } +#define APPLE_GPU_VARS_GUID EFI_GUID(0xfa4ce28d, 0xb62f, 0x4c99, \ + 0x9c, 0xc3, 0x68, 0x15, 0x68, 0x6e, 0x30, 0xf9) + +static efi_char16_t gmux_gpu_active_name[] = L"gpu-active"; + +static void gmux_write_switch_state_efi(struct apple_gmux_data *gmux_data) +{ + efi_guid_t guid = APPLE_GPU_VARS_GUID; + u32 active = gmux_data->switch_state_display == VGA_SWITCHEROO_IGD; + efi_status_t status; + + if (!efivar_is_available() || + !efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) + return; + + status = efivar_set_variable(gmux_gpu_active_name, &guid, + EFI_VARIABLE_NON_VOLATILE | + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS, + sizeof(active), &active); + if (status != EFI_SUCCESS) + pr_warn("writing gpu-active failed: 0x%lx\n", status); + else + pr_debug("gpu-active: %u\n", active); +} + static int gmux_switchto(enum vga_switcheroo_client_id id) { apple_gmux_data->switch_state_ddc = id; @@ -497,6 +524,8 @@ static int gmux_switchto(enum vga_switcheroo_client_id id) apple_gmux_data->switch_state_external = id; gmux_write_switch_state(apple_gmux_data); + if (apple_gmux_data->type == APPLE_GMUX_TYPE_MMIO) + gmux_write_switch_state_efi(apple_gmux_data); return 0; } @@ -1240,6 +1269,15 @@ static void gmux_remove(struct pnp_dev *pnp) kfree(gmux_data); } +static void gmux_shutdown(struct pnp_dev *pnp) +{ + struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp); + + gmux_write_switch_state_efi(gmux_data); + + gmux_remove(pnp); +} + static const struct pnp_device_id gmux_device_ids[] = { { .id = GMUX_ACPI_HID }, { } @@ -1254,6 +1292,7 @@ static struct pnp_driver gmux_pnp_driver = { .name = "apple-gmux", .probe = gmux_probe, .remove = gmux_remove, + .shutdown = gmux_shutdown, .id_table = gmux_device_ids, .driver = { .pm = &gmux_dev_pm_ops, @@ -1265,3 +1304,4 @@ MODULE_AUTHOR("Seth Forshee "); MODULE_DESCRIPTION("Apple Gmux Driver"); MODULE_LICENSE("GPL"); MODULE_DEVICE_TABLE(pnp, gmux_device_ids); +MODULE_IMPORT_NS("EFIVAR"); -- 2.55.0